Reduced graphene oxide decorated Pt activated SnO₂ nanoparticles for enhancing methanol sensing performance

Methanol gas sensors with excellent performances are in great demand to monitor the industrial manufacture and many household products. We have synthesized Pt-activated SnO₂ nanoparticles partly wrapped by reduced graphene oxide (RGO) for high performance methanol gas sensor application. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) results indicated that the platinum element is present in two types, including metal (Pt) and tetravalent metal oxide (PtO₂) in the Pt-activated SnO₂ clusters. The SnO₂ nanoparticles with an average size of about 10 nm are in form of cluster type and there are abundant random wormhole-like pores throughout each cluster. The gas responses of the pristine SnO₂ gas sensor, Pt-activated SnO₂ gas sensor and the RGO-assisted sensors toward 40 ppm methanol at the relatively low operating temperatures (110 °C) were 7.8, 38.5 and 60.1, respectively. And the sensor exhibited shorter response time with only 6 s. The excellent gas-sensing properties are mainly attributed to the improved electronic interaction and the reduced potential barrier between RGO and Pt/SnO₂.